Fuel tank vent.

H8z2luze said
am using a similar filter on a LS1 in my truck. They came in corvettes. It's actually a regulator and filter in one. Whatever the engine won't use or what's over the psi of the regulator it diverts it back to the tank. I wonder if it's a similar deal

My understanding is there is a very small orifice that bleeds the vapor and a tiny amount of fuel but you still get more than enough fuel to run the engine.